In the last 15 years, calibrachoa has emerged as one of the most vibrant vegetative annuals crops. The versatile plants are ideally suited to hanging baskets, patio containers and window boxes. The first series to make a splash globally was Million Bells by Suntory. Technical experts from Suntory share their tips for producing calibrachoas.
Calibrachoa is a facultative long-day plant. Provide long days during propagation and production, if possible, although modern breeding has made great advances in bringing forward the flowering timing.
Once cuttings are rooted and established, cuttings can be given a pinch to encourage a bushy plant. This is usually around three to four weeks after sticking. Sometimes this is not carried out by rooting stations and should be done by the grower at potting or just afterwards.
Avoid overwatering stress, as this can lead to nutritional problems.
Rooted cuttings should be potted up as soon as possible into 4-inch to 10-inch pots, using open, free-draining growing media with a pH of 5.2-6.0 and incorporating a balanced fertilizer. Aim for an EC of 1.8-2.0.
Temperatures of the crop at this stage should be 65-70°F for the first couple of weeks. This will enhance root development. Do not overwater. After two weeks, the crop is best grown at 60-65°F.
Watering is a key issue with this crop. High levels of water will encourage root death, so a little-and-often regime is encouraged when plants are young to provide as much air to the crop as possible.
The crop may require pinching to encourage the right habit and breaks to get a bushy and spreading plant.
The crop should be watered uniformly throughout its life using a balanced liquid fertilizer at 200 ppm. Water plants prior to wilting and allow the substrate to dry out between waterings. This will reduce the risk of root rots.
Research is being conducted on the use of growth regulators on this crop. B-Nine works well on calibrachoa. Pinching the plants to encourage the correct shape also acts as a growth control.
4-inch pots–four to six weeks from liner
6-inch pots–six to eight weeks from liner
10-inch pots–10-12 weeks, three liners
4-inch pots–one to two pinches
6-inch pots–two pinches
10-inch pots–two to three pinches
Whitefly (Trialeurodes vaporariorum)
Western Flower Thrips (Frankliniella
Red Spider Mite (Tetranychus urticea)
Botrytis cerea (gray mold)
Thielaviopsis basicola (black root rot)